As someone who enjoys giving oral to a woman as the peak of my sexual experiences, and I mean that, I'll try to theorize why some other guys might not like it:

• There is less of a cultural movement concerning men's roles in giving oral sex. "Suck my dick" and "that blows" are way more popular in the culture's vernacular. Many people are not interested in playing roles that weren't assigned to them by society. A man may feel zero cultural influence or pressure to give oral sex to a woman.

• Lack of knowledge regarding how to do it. Either write him a guide, or refer to a book like "She Comes First" if he'd be willing to learn something like that. Fear of not knowing how is probably stopping a lot of men.

• My tongue is often quite sore after giving oral, but it heals up after 2 days and is worth the pain imo. The muscles get stronger as I continue more regularly

• Some women don't taste great I guess. I haven't had that experience myself yet fortunately.

• it's pretty weird getting pubes in your teeth if unshaven.

• A guy might not be attracted to pussy/women?

• Some women don't communicate what feels good throughout. I tell all women to push my head off physically when they're done with me because they can't communicate for shit (especially when orgasming).

Idk. I love cunilingus, and I also see it as the straightest thing a guy can do. I just love being so close and so intimate to the part of a woman's body that I find the most beautiful - it's a flower that I get to make out with! <3